Dual offset cantilevered spring suspension

Abstract

A vehicle suspension system is provided with dual offset cantilevered leaf springs. A forward and a rearward extending leaf spring are both mounted to a vehicle axle in a longitudinally overlapping transversely offset manner. The forward and rearward springs are also connected at their extended ends to a structural frame member of the vehicle. The longitudinally overlapped mounting of forward and rearward extending springs allows the deflection per given load of the suspension system to be increased while at the same time minimizing the overall length of the spring suspension system. The transverse offset of the spring may provide for a decreased turning radius by allowing greater clearance between the wheel and suspension system.

What is claimed is: 
     
       1. A truck frame suspension system comprising: an axle positioned transversely to said frame, said axle having a pair of mounting plates disposed adjacently transversely near an end thereof;   a first leaf spring having a first end mounted as a cantilever to one of said pair of mounting plates and extending in a first direction to a distal end attached to the truck frame; and   a second leaf spring having one end mounted as a cantilever to the other of said pair of mounting plates and extending in a second direction opposite of the first direction to an opposite end attached to the truck frame, said second leaf spring longitudinally overlapping said first leaf spring and being transversely offset therefrom.   
     
     
       2. A vehicle frame suspension system as described in claim 1 further including said first spring having an eyelet at the distal end thereof. 
     
     
       3. A vehicle frame suspension system as described in claim 1 further including a shackle being pivotally attached to said frame and said opposite end of second spring being attached to said shackle. 
     
     
       4. A vehicle frame suspension system as described in claim 1 wherein said first spring has a spring rate which differs from the spring rate of said second spring. 
     
     
       5. A vehicle frame suspension system as described in claim 1 wherein said first spring is semi-elliptical in its free state. 
     
     
       6. A vehicle frame suspension system as described in claim 1 wherein said second spring is a tapered leaf spring.